一个倒计时时钟：
countdown.js
var test_val;
function el(id) {
if (document.getElementById) {
return document.getElementById(id);
} else if (window[id]) {
return window[id];
}
return null;
}
function UpdateDisplay()
{
document.tform1.ctd.value = GetCountdownTime(document.tform1.cs.value);
document.tform2.ctd.value = GetCountdownTime(document.tform2.cs.value);
document.tform3.ctd.value = GetCountdownTime(document.tform3.cs.value);
document.tform4.ctd.value = GetCountdownTime(document.tform4.cs.value);
test_val = el("test_val")
test_val.innerHTML = GetCountdownTime(document.tform4.cs.value);
timer1=setTimeout(’UpdateDisplay()’,250);
}
function GetCountdownTime(date_str)
{
return( TimeToHMS( GetSecond( new Date(date_str))));
}
/* get the countdown initial time to a specific time */
function GetSecond(date_count_to)
{
date_now = new Date();
time_now = date_now.getTime();
time_count_to = date_count_to.getTime();
if(time_now >= time_count_to )
{
ret_val = 0;
}
else
{
ret_val = Math.round( ( time_count_to - time_now ) / 1000.0 );
}
return (ret_val);
}
/* convert seconds value to H:MM:SS format */
function TimeToHMS(seconds)
{
sec = seconds % 60;
temp = ( seconds - sec ) / 60;
minute = temp % 60;
hour = (temp - minute) / 60;
if(!(isFinite(sec) && isFinite(minute) && isFinite(hour))) /* invalid time */
{
return ("");
}
time_str = hour;
time_str += ":";
time_str+=(minute<10)?("0"+minute):minute;
time_str+=":";
time_str+=(sec<10)?("0"+sec):sec;
return (time_str);
}
测试文件：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "
http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html"; charset="utf-8">
<title>Test the countdown function</title>
<! include the javascript file >
<script language="JavaScript" src="countdown.js" type="text/JavaScript"><!--
//--></script>
</head>
<body>
Test1: <span id="timer1"></span><br>
<script>
<!--
var timer1;
var time_val1=6000;
function updateTimer1()
{
timer1 = el("timer1")
timer1.innerHTML = TimeToHMS(time_val1);
time_val1--;
setTimeout(’updateTimer1()’, 1000);
}
updateTimer1();
// -->
</script>
Test2: <span id="timer2"></span><br>
<script>
<!--
var timer2;
var time_val2=66000;
function updateTimer2()
{
timer2 = el("timer2")
timer2.innerHTML = TimeToHMS(time_val2);
time_val2--;
setTimeout(’updateTimer2()’, 1000);
}
updateTimer2();
// -->
</script>
Test1000: <span id="timer1000">ii</span><br>
<script><!--
var timer1000;
var time_val1000=78900;
function updateTimer1000(){
timer1000 = el("timer1000");
timer1000.innerHTML = TimeToHMS(time_val1000);
time_val1000--;
setTimeout(’updateTimer1000()’, 1000);}
updateTimer1000();
// -->
</script>
</body>
</html>
追问我说的是循环倒计时的